Hen HouseDnestrDneprDaugava

Operational ballistic missile early warning is providing by 11 large HEN HOUSE detection and tracking radars at six locations on the periphery of the USSR. These radars can distinguish the size of an attack, confirm the warning from the satellite and over-the-horizon radar systems, and provide target-tracking data in support of antiballistic missile (ABM) deployments.

There are three variants of the HEN HOUSE radar:

Dnestr - 6,000 ft2 large straight array

Dnepr - 3,000 ft2 large Y-array

Daugava - 1,000 ft2 small Y-array

The Dnestr above-the-horizon early warning radars were developed by the Radio-Electronic Research Institute (NIRI) of the Soviet Academy of Sciences under the supervision of A. Mints (Chief Designer Yu. Polyak). The maximum detection range of the radars for a target with a range of 1,600 kilometers was 1,440 kilometers, for a missile launched at 3,200 kilometers the detection range was 2,400 kilometers, and for an intercontinental missile [with a range of 8,000 kilometers] the detection range was 3,520 kilometers.

In 1967 the first Dnestr specialized radiotechnical station was tested in Kazakhstan. The first Dnestr-type radars, designed to warn of a missile attack and monitor outer space, were deployed in Kazakhstan and Siberia in 1967-1968. The Dnestr-type radar deployed in Kazakhstan was the first Soviet radar designed to track satellites. In 1968, a radar complex consisting of eight Dnestr radars designed to monitor outer space was successfully tested, forming a continuous radar barrier covering a sector of over 5,000 km in length and up to 3,000 km in altitude.

In 1960-61, the Mints Radiotechnical Institute (RTI) began designing a fundamentally new radar, the Dnestr-M type, which for the first time used a pulse compression method destined to process the incoming signals emitted by powerful radars. This made it possible to take full advantage of the radar's high accuracy and resolution characteristics. Construction of the upgraded Dnestr-M radar, which was to be stationed in the trans-polar area (RO-1 in Murmansk) and Latvia (RO-2 in Riga), began in 1963-1964. The state tests of the Dnestr-M radar were conducted between 1968 and 1976 in the trans-polar area.
Tests of these radars within radiotechnical complexes deployed in the Trans-Polar regions, in Latvia and near Moscow were completed in 1976.

In 1969, in cooperation with the customer and other enterprises of the industry, the Mints Radiotechnical Institute (RTI) developed the Ekvator project, which defined the major principles of the Soviet missile attack warning [MAW] system. To set an uninterrupted radar field in the western, southwestern, and southern missile danger zones, radar centers were constructed between 1968 to 1972 in Western Ukraine, Crimea, Kazakhstan, Siberia and the Kola Peninsula. The Dnepr radars developed by the Mints Institute formed the basis for these centers. Together with the Daryal radars deployed later, these radars formed the basis for the Soviet ground-based MAWS. In early 1970s, building of the new Dnepr radars began near Riga, Mukachevo, Sevastopol, Irkutsk, and Lake Balkhash.
The main distinguishing features of the Dnepr radar and its modified Dnepr-M version are the improved signal processing methods employed and, particularly, the coherent accumulation of pulse bursts, better control of the radar antenna radiation pattern and enhanced noise immunity.

To ensure that the information obtained under heavy noise conditions caused, for example, by the northern lights in the polar ionosphere, is reliable, an additional Daugava receiving station was erected at the northern center. It was equipped with a large-aperture phased array having phase-phase control capability and featured a hybrid super-high frequency microwave technology that was used there for the first time.

On the basis of the Dnepr and Daugava radars, new generation radars of the Daryal series were designed.